The present invention relates to the supplying of air to a combustion chamber and particularly to the cleaning of nozzles through which air is delivered to a fluidized-bed reactor. More specifically, this invention is directed to a siphon-type air nozzle having a tubular support which is in fluid communication with the discharge end of the nozzle and especially to a nozzle assembly wherein a pressurized air line may be connected to the support for use in cleaning the air nozzle. Accordingly, the general objects of the invention are to provide novel and improved methods and apparatus of such character.
Siphon-type air nozzles are well known for use in fluidized-bed reactors. Published German Patent Application No. 3224909 discloses such a nozzle. The prior art siphon-type air nozzles are designed to prevent unburned fuel, ashes and bed material from falling out of the furnace, through the fireproof sheathing of the grid plate, into the plenum chamber i.e., the wind box, by which the air or other gaseous source of oxygen for supporting combustion is supplied to the reactor. However, during operation, the discharge ends of the prior art nozzles nevertheless become partially or completely coated with unburned fuel, ashes and bed material. This coating, by reducing the size of the nozzles, affects the air intake to the furnace. Partially coated or clogged air nozzles are hard to clean or cannot be cleaned at all. Cleaning the air nozzles or replacing the air nozzles, fireproof sheathing or either grid plate are lengthy operations with correspondingly high costs.